Add Discord badge link to CONTRIBUTING.md

Added a badge link to join the CommitPulse Discord server for collaboration and support.

Author: JhaSourav07

CONTRIBUTING.md

@@ -219,6 +219,8 @@ Fixes # (issue number)
 - [ ] (Recommended) I joined the CommitPulse Discord server for faster collaboration, mentorship, and PR support.
 ```
 
+[![Join CommitPulse Discord](https://img.shields.io/badge/Join-CommitPulse%20Discord-5865F2?style=for-the-badge&logo=discord&logoColor=white)](https://discord.gg/Cb73bS79j)
+
 > **PRs without a visual preview for any SVG-touching changes will be asked for one before review.**
 
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